I wasn't too sure what forum to put this in, but this one seemed the most appropriate candidate. This thread will be asking quite a few questions, so I thank anyone in advance for helping me.

I've been talking with a local charity that distributes food and shelter to homeless and impoverished people, and we've come up with a bit of an idea, but it is going to take months of planning and plenty of help from experienced bicyclists.
Since many people around are always looking to help charities but don't know how, we were thinking of going around and asking for pledges. They can pledge a certain amount of money per mile that I bike.

There's a bit of a snag, though: I have never toured on a bike. I don't know how to rig a bike with a backpack, I have no idea what kind of bike to buy (my current one is a very old racing bike, and ones before that were Wal-Mart bought mountain bikes), what to pack, etc.

Before I get down to the questions, let me give some background.
About a year ago I completely quit smoking and got back into shape. My lungs are healed (I had the habit for 5 years), and I'm happy about it. I weigh 200 pounds, I do cardio 2 hours a day and bike ten miles, I jog, and I hit the gym a couple times a week to squat and work on my upper and lower (with special emphasis on my legs). I'm a vegetarian, but I mainly eat brown rice (plenty of protein and vitamins), and I take One-A-Day Maximum vitamins. I also don't drink soda and I stay away from junk food.

The Questions:

-What additional training should I do?
-What bike should I get? Price?
-How do I rig up a bike with supplies?
-What do I bring with me?
-What should I expect on a-possibly-cross country tour?
-What sort of gadgets help (security, etc.)?
-What are the basics of touring?
-Am I out of my mind for thinking about this?

Again, thank you guys for any and all help. I'm sure in my convictions that I want to do this, and I hope it's a possibility.

I have never toured on a bike. I don't know how to rig a bike with a backpack, I have no idea what kind of bike to buy (my current one is a very old racing bike, and ones before that were Wal-Mart bought mountain bikes), what to pack, etc.

You can get a good touring bike, but you may first want to take your existing bike down to your local bike shop and ask them if it's suitable for what you're planning. If it is, you'll have a lot less expense.

Don't try to rig a backpack to your bike. You can get good racks and panniers for modest prices. My rear rack set me back $15. You can get good large rear panniers starting at less than $70. Prices will increase if you want something larger, fancier or fully waterproof.

Yeah, get panniers. Youre in shape for touring. Ive smoked on tour and could still get 90+ days.

Your perfectly safe in the US as long as your not arrogant to small town folk. I find wearing jeans and drinking beer at night keeps you safe and gets you put up on couches most of the time.

That racing bike is probably your best bet for road touring, and you could possibly swap your moutain bike gearing onto it. If you post all your bikes someone here would know what would be interchangable.

You can camp pretty much anywhere for free as long as you stay out of sight and leave at dawn.

Few changes of clothes, tent, sleeping bag, tools, tubes, and 3 liters of water holding capacity - minimum. Anything else you dont think of you can buy on the trip, the abundance of retail across the country is pretty much constant. Youll never go 150 miles with out some kind of strip mall unless you go out of your way to. Oh yeah, a box of gallon ziplock bags will waterproof everthing (clothes, books, maps, electronics, seperate your laundry, store food, and you can pee in them when its too cold to leave your tent (or dogs are stalking your tent).

Blackburns expedition rear rack holds up great and you can find it US30-40.

Adventure cycling (.com) assosiation routes and maps give you detailed routes, the distances between towns, and the services in those towns; you dont even really need to plan your trip besides the morning before you start riding.

Actually, scratch the advice about using your old racing bike, specifically in reference to the old steel wheelset it probably still has on it. Give all the info on that bike and an expert on gear here will let you know what the deal is (and specify if your on a budget or youll be told you need to buy a $2000 bike, a $400 wheelset, or a $100 saddle, etc.).

If in doubt, you want either a touring bike or a "serious" hybrid/hybrid (no suspension, long chainstays) that fits you well; either drop bars, trekking bars or flat bars with bar ends; front and rear racks and panniers; and relatively lightweight gear (eg. google search ultralight backpacking). Tyres 32-37mm if 700c (28mm still OK on good road), 1.5" slicks if 26" wheels. You definitely want a bike recent enough to have aluminium rims, and you want at least one low gear (one turn of the pedals should give you less than a full rotation of the back wheel in your lowest gear).